1. Field of the Invention
The present invention relates to audio data recording/reproduction devices, and more particularly, to an audio data recording/reproduction device that can carry out digital high speed dubbing of audio data using an optical recording medium or a magneto-optical recording medium, and an audio data dubbing system using such devices.
2. Description of the Background Art
In recent years, a system is proposed such as the commonly called minidisc system that records compressed audio data intermittently on a disc using the magneto-optical recording principle. In the recording device of such a minidisc system, audio data of approximately 2 seconds of each channel provided from an audio signal source are digitalized and data-compressed to, for example 1/5, to be stored in a memory. When compressed audio data of a predetermined recording unit (1 cluster=36 sectors: here 1 sector is 2332 bytes) are stored in the memory, recording of compressed audio data to the disc is carried out.
In accordance with such a recording method using a memory, recording of compressed audio data to a disc is carried out intermittently with compressed audio data of 1 cluster as the recording unit. Therefore, even if there is a tracking error of the head due to vibration and the, like during recording to result in recording failure of compressed audio data to a disc, the recording operation of the compressed audio data can be carried out again before the start of recording operation of compressed audio data in the next recording unit. Therefore, drop out or termination of recorded data due to recording error can be prevented.
In a device that reproduces compressed audio data from a disc having digital compressed audio data recorded therein using the optical recording principle or the magneto-optical recording principle, a method is proposed in which compressed audio data reproduced intermittently from a disc is first stored in a memory and then sequentially read out therefrom to carry out continuous reproduction of compressed audio data.
According to such a reproduction method using a memory, reproduction of audio data from a disc is carried out intermittently. Therefore, even if reproduction of compressed audio data from a disc fails due to a tracking error of the head by vibration during reproduction or due to a scratch on the surface of the disc, drop out or termination of reproduced data due to reproduction failure can be prevented by sequentially reading out compressed audio data continuously which have already been stored in a memory and by carrying out again the reproduction operation of the compressed audio data before the start of reproduction operation of the next compressed audio data. Such a recording/reproduction device of a minidisc system is disclosed in a copending U.S. patent application Ser. No. 964,787 assigned to the same assignee of the present application.
A method of carrying out high speed dubbing of digital audio data using 2 units of disc recording/reproduction devices is proposed. Such a method is disclosed, for example, in a copending U.S. patent application Ser. No. 876,365 assigned to the same assignee of the present application. In brief, this method is implemented where audio data recorded on a disc of the reproduction side is read out by a disc reproduction device at the reproduction side using an optical pickup. The read out audio data is subjected to a predetermined decoding process and provided to a disc recording device at the recording side. The provided reproduced audio data is subjected to a predetermined encoding process in the disc recording device at the recording side and then recorded on a disc of the recording side by a head.
In the above-described dubbing method, the digital audio data reproduced from the disc of the reproduction side is provided to the device at the recording side without being stored in a memory. Therefore, if data reproduction fails due to tracking error caused by vibration or due to a scratch on the surface of the disc in the device at the reproduction side, the data not reproduced can no longer be recorded on the disc of the recording side. Furthermore, because the data for recording is recorded on a disc without being first stored in the memory at the recording side, if recording fails due to tracking error at the recording side even when reproduction of data at the reproduction side is possible, the data can no longer be recorded on the disc of the recording side.
Such problems of the conventional proposed dubbing method can be solved as follows when a dubbing system is implemented using the above-described minidisc system. More specifically, even when reproduction of audio data fails in the device at the reproduction side, the reproduction operation can be carried out again as mentioned above, wherein the reproduced audio data obtained by the re-reproduction operation is provided to the device at the recording side to be recorded on a disc thereof. Thus, proper dubbing with no interruption of audio data can be carried out continuously. Furthermore, even when recording of audio data fails at the device of the recording side, the recording operation can be carried out again, so that proper dubbing with no terminated audio data can be carried out continuously.
However, the above-described system using a minidisc generates the following problems when reproduction fails continuously in the device at the reproduction side or when recording fails continuously in the device at the recording side. For example, consider a case where recording of audio data to a disc is prevented continuously by some cause in the device at the recording side while reproduction of audio data is continuously carried out properly in the device at the reproduction side. Because provision of audio data from the device at the reproduction side to the device at the recording side and storage of the audio data to the memory in the device at the recording side are continued, the memory in the device at the recording side will eventually overflow.
Considering a contrary case where reproduction of audio data from a disc is prevented by some unrestorable cause such as scratch of a disc in the device at the reproduction side, the recording operation of data to a disc in the recording side device can never be carried out even though the recording side device retains a standby state of the recording operation, since the amount of supplied audio data for recording in the memory at the recording side never attain the predetermined recording unit.
Thus, a conventional dubbing system using a disc recording/reproduction device had the problem that proper dubbing could not be carried out since audio data to be recorded to the disc of the recording side is dropped or the recording operation never start when a reproduction disable state at the reproduction side or a recording disable state at the recording side continues.